Please tell me what screens you guys are using or are going to use with your RS1 projectors. I'm sure a lot of this is in the owners thread but I'd like to get a nice summary here.

Art

I've got a 110" ST 130 Microperf.

128" 2.35 Carada Brilliant White (2.35 setup by 1st week of May) and 110" Vutec Matte White (currently setup.)

I have a brand new 110/54x96 Da-Lite Cinemavision w/1.3 gain. It is a much better screen than Da-Lite earlier Cinemavision screens. The frame is less reflective than previous Cinemavision screens and the back of the sreen is now solid black, preventing loss of light and impact through the screen and reflexions from the wall.

Your topic's a little broader, but there's already an RS1 screen thread here (http://www.avsforum.com/avs-vb/showthread.php?t=826301).

Anyway, I'm using a 100" Carada BW.

139" wide 2.35:1 High Power

Right now, I'm using white fabric to dial in the size and location, but I plan to order a 100" Carada BW this week.

Just ordered a 134" Diag. 16X9 Carada Criterion BW. Currently have a 110" Firehawk.
Main seating is 18-20' from the screen. BTW, David Giles at Carada is a pleasure to deal with.

122" wide 2.35:1 high power (Dalite)

Personally, I don't find these types of "list your equipment" threads very enlightening unless they are accompanied by some comments on how the combination is working out (e.g. how the JVC projector is looking on the same screen compared to a previous screen, or how a new screen as brought out X good/Y bad features of the JVC, or satisfaction with brightness/black level/shadow detail, or "I have X screen with the JVC but my impression is that I may need to switch to Y screen for these reasons..." etc).

Otherwise just listing equipment is like writing: "Hey guys, yesterday I saw the JVC on a 110 Firehawk screen!"....and providing no details of how the combination worked together. Not too enlightening.

In other words, I hope people will supplement their responses with some detail. Thanks.

Personally, I don't find these types of "list your equipment" threads very enlightening unless they are accompanied by some comments on how the combination is working out (e.g. how the JVC projector is looking on the same screen compared to a previous screen, or how a new screen as brought out X good/Y bad features of the JVC, or satisfaction with brightness/black level/shadow detail, or "I have X screen with the JVC but my impression is that I may need to switch to Y screen for these reasons..." etc).

Otherwise just listing equipment is like writing: "Hey guys, yesterday I saw the JVC on a 110 Firehawk screen!"....and providing no details of how the combination worked together. Not too enlightening.

In other words, I hope people will supplement their responses with some detail. Thanks.

More could be learned but I'm looking to see the general amount of light guys are comfortable with and if they see side effects from various gain numbers, manufacturers etc.

Art

I've got a 110" ST 130 Microperf.


Ditto on this.

123" diagonal Screen Innovations Reference model 1.3 gain.

http://www.screeninnovations.com/fixed.html

126" (110"x62") Dalite HP, and I like it very much. Room is essentially dark but with light-colored ceiling (screen top edge 16" from ceiling).

65 x 116 HP.

Using low lamp even though I'd like it brighter, but I'm saving high mode for when the lamop is older.

110" ST130 16x9. Using low lamp setting and the combo looks fantastic.

120" 16 x 9 SilverStar.

I'm still waiting for the RS1 to arrive (3rd wave, 1 month to go). When it gets here it will definitely be fitted with a Hoya HMC ND2 filter as the image will be to bright without it. I'm still using one of these filters with my Infocus 4805 that has over 1500 hours on the lamp.

I plan on using a Carada 80" diagonal 1.78:1 High Contrast Gray (0.8 gain, I think) than I got for use with an Infocus ScreenPlay LS110 (massive 600:1 contrast ratio).

Eventually I'd like to move up to a 104" diagonal 2.35:1 Carada Brilliant White, but that's a ways off in the future.

I am 3rd round, but I will be using a ST130 94" diag.

120"W Screen Research ClearPix2... 0.95 gain, acoustically transparent

RS1 Setup at close to min. throw (~14.5') and used in Normal Lamp

110" diagonal HP - low lamp

Studiotek 130 110" diagonal.

I don't have the RS1 mounted (it's positioned at center of screen) and I'm seeing the screen material. I'm hoping this will disapear when it's ceiling mounted, but I'm not sure.

I have it at max throw... thinking of going larger. I have plenty of light... and when the bulb dims I'll just buy another.... :-)

Hmmm, gotta ask... Art, why do you care? Compiling the info for someone else or are you considering a 2nd, smaller home theater? :-)

Stewart 110” Perforated THX Front Projection Screen

133" diagonal Stewart Firehawk MicroPerf

100 inch ST130, 16x9.

60 x 144

2.40 High Power. Awesome :)

I'll put this up against the best images available.

Hmmm, gotta ask... Art, why do you care? Compiling the info for someone else or are you considering a 2nd, smaller home theater? :-)

Well one thing that has started me thinking is both the RS1 and and HT 5000 demos I did in my theater. There is something very very compelling about high fL. I know we all say ones eyes adjust etc but I'm convinced that this simply isn't the case.

So I'm just getting an idea of the way each of you guys see this and how you are dealing with it to get the best for your installs.

Recently, I read a comment from Joel Silver saying that for screening rooms the starting number should be 20fL. For a large screen that is a lot of light to maintain and right now, there are few good and no great solutions for achieving that kind of light IMO.



Art

The High Power is a great solution.

1. Due to its retroreflectivity no other screen can deliver its uniformity on a flat plane. when going scope

2. It can deliver almost 3 times the light of a matte white screen.

3. You will not see the surface.

60 x 144 2.40 High Power. Awesome :)

I'll put this up against the best images available.

Willing to bring it down under? :p

The High Power is a great solution.

1. Due to its retroreflectivity no other screen can deliver its uniformity on a flat plane. when going scope

2. It can deliver almost 3 times the light of a matte white screen.

3. You will not see the surface.

Sorry,not great for a projector mounted on the ceiling , for anyone wanting an AT solution , for those with tiered seating, or a wide theater.

Art

1. AT no
2 theater seating yes
3. wide? yes and no.

Most couples can sit in the desired location 95% of the time. when you have guests they may see a little reduction in brightness in the outer seats. You'd probably be surprised by how much gain you get even off axis.

1. AT no
2 theater seating yes
3. wide? yes and no.

Most couples can sit in the desired location 95% of the time. when you have guests they may see a little reduction in brightness in the outer seats. You'd probably be surprised by how much gain you get even off axis.

Where do you get 3.0 gain in degrees vertically and horizontally and it is retroreflective right ? What about ceiling mounted projection systems (or in my case out of the room at ceiling height) ?

Art

I think a lot depends as well on the distance of your seating and projector from the screen. The farther back the projector and seating, the smaller the angle of incidence yielding a higher gain.

If you look at the attached HP gain chart (yellow graph), anywhere past 18deg and the gain is below 1.0.

0 degrees = 2.8 gain
5 degrees = 2.6 gain
10 degrees = 2.1 gain
15 degrees = 1.4 gain
20 degrees = 0.9 gain
25 degrees = 0.8 gain

http://www.audiogeneral.com/DaLite/front_untensioned.gif

Joe,

Does the "axis" mean only the center of the screen? So if you are sitting within the screen width, but 20 degris off the center of the screen, you are at less than 1 gain. Or does the the measurement start off the screen?

Tony

I think the relevant angle here is that between your eyeball to a point on the screen and back to the lens. E.g., if your eyeball is close to the lens, this angle is ~0 deg FOR ANY POINT ON THE SCREEN. And if you sit right at the edge of the screen, you can easily do the geometry to determine that angle; but note: the angle is almost independent of the point on the screen that you use--meaning that even though the image will not be as bright as if you were near the lens, the entire screen will have very close to the same brightness.

PS But I agree with Art; the HP is not the best for the parameters of his setup.

Thanks ! :)

Art

But I agree with Art; the HP is not the best for the parameters of his setup.

What happens if you are off axis in two directions with the High Power ? What I mean is, using rough calculations with a ceiling mount in my theater, taking into consideration only the vertical , my front row looks like about 0.7 gain, my middle row 1.4 gain, and my back row 1.7 gain. What about if you weren't in the center of the room with these gain numbers does it go down further, I assume it does ? My outside seats in the front row are about 20 degrees off axis my second row about 15 degrees.

Art

What happens if you are off axis in two directions with the High Power? What I mean is using rough calculations with a ceiling mount in my theater, taking into consideration only the vertical , my front row looks like about 0.7 gain, my middle row 1.4 gain, and my back row 1.7 gain. What about if you weren't in the center of the room with these gain numbers does it go down further I assume it does.

Art


I'm sure there's a 3 dimensional scientific mathematical calculation, but that hurts my brain. :p

A simple unscientific way of calculating this would be use the center of the screen as reference. If your projector is ceiling mounted calculate the angle from the lens to screen center. Say this number is 15 degrees

Now calculate the angle of the viewers eyes in the off center seating location to the center of the screen. Say this number is 10 degrees.

Total 25 degrees = 0.8 gain

What happens if you are off axis in two directions with the High Power ? What I mean is, using rough calculations with a ceiling mount in my theater, taking into consideration only the vertical , my front row looks like about 0.7 gain, my middle row 1.4 gain, and my back row 1.7 gain. What about if you weren't in the center of the room with these gain numbers does it go down further, I assume it does ? My outside seats in the front row are about 20 degrees off axis my second row about 15 degrees.

Art

Since I always planned to mount my pj on a stand, about 50" above the floor, I've really only thought much about the horizontal viewing angles; and for my viewing distance (~1.3 to 1.4 SW), one can easily go to the L/R edges of the screen, or a ft or 2 beyond, and have very good results. (And since my room is relatively narrow, that's plenty for me).

For a reasonably high ceiling mount, and a very close front row, I certainly agree with you that the HP would not be ideal, as your 0.7 gain figure indicates. Again, though, even with a reduced gain of 1.4 or 1.7, I think the brightness over the whole screen FOR EACH STATIONARY VIEWER would be reasonably uniform. Whether this is enough gain of course will depend on other considerations.

PS I didn't comment on your 'two dimensional' viewing angle query. I think the HP performs the same horizontally and vertically. So the relevant angle should still be that from eyeball, to point on screen, to lens; and you can use different points on the screen to see how much this angle varies for a given viewing location.

I'm sure there's a 3 dimensional scientific mathematical calculation, but that hurts my brain. :p

A simple unscientific way of calculating this would be use the center of the screen as reference. If your projector is ceiling mounted calculate the angle from the lens to screen center. Say this number is 15 degrees

Now calculate the angle of the viewers eyes in the off center seating location to the center of the screen. Say this number is 10 degrees.

Total 25 degrees = 0.8 gain

I know that ceiling mounting for HP is no good for me obviously, but just as an exercise this means that if it were in my theater it would mean that the majority of my seats the gain would be beteen 0.8 and 0.7 based on the supplied chart and only three seats would have a positive gain.

Art

110" DaLite High Power.

Light (but not white) colored sidewalls and ceiling.

Mid throw. Low lamp. Projector mounted about 3-4 feet above head. Using a very small amount of horizontal shift and slightly more vertical lens shift (not exactly sure how much).

Pictue is outstanding. Very punchy and bright for the size. (Happy Feet on Blu-Ray was gorgeous) When I'm switching inputs the "blue" screen just about blinds me!:) Movies are vibrant but not fatiguing in their brightness with the HP.

I know that ceiling mounting for HP is no good for me obviously, but just as an exercise this means that if it were in my theater it would mean that the majority of my seats the gain would be beteen 0.8 and 0.7 based on the supplied chart and only three seats would have a positive gain.

Art

Indeed, in your install case the gain of the HP is being handicapped by a compounding of both a ceiling mount and off center viewing locations.

Consider that a screen does nothing more than receive and based on it's characteristics, redirects light. The HP concentrates and redirects light thrown at it back to the origin at a given intensity (gain).

A very inexpensive way of testing this out for yourself, if you're inclined, would be to order a manual pull down for a few bucks to try out with your setup. They're pretty easy to sell in the AVS forum once you're done with it, but at least you'll know how it works in your theater (which I think is awesome :) ).

Tryg's done some terrific legwork testing (http://www.avsforum.com/avs-vb/showthread.php?t=262466) and documenting screens. Have a look at his shots of the HP and SS effects on viewing angles. The HP cone is very real. Note the change in brightness of the white squares, even at 10 degrees. The HP is on the right side.

http://home.comcast.net/~tryghoff/anglesSSHP.JPG

The HP cone is very real. Note the change in brightness of the white squares, even at 10 degrees. The HP is on the right side.

http://home.comcast.net/~tryghoff/anglesSSHP.JPG

So that is only 10 dgrees off axis for HP ?

Art

Well one thing that has started me thinking is both the RS1 and and HT 5000 demos I did in my theater. There is something very very compelling about high fL. I know we all say ones eyes adjust etc but I'm convinced that this simply isn't the case.


Art,

I'll be interested to see your comments on this once you live with the image for a while. I started at 12fL with the Cineo but quickly found this *way* too bright for comfort in my room - I now run at 7fL and even that can make you squint in bright daylight scenes...

Mark

So that is only 10 dgrees off axis for HP ?

Art

The viewing angle in that pic ranges from 0, 10, 20, 30 & 40 degrees, as marked on the left hand side of each pic.

Art,

I'll be interested to see your comments on this once you live with the image for a while. I started at 12fL with the Cineo but quickly found this *way* too bright for comfort in my room - I now run at 7fL and even that can make you squint in bright daylight scenes...

Mark

Mark,
When I watched quite a bit of King Kong at 23fL it was a totally different experience and the first time in a while I could say I felt like it was a step up. On my system and with thr RS1 on the same screen the outdoor scenes are very satisfying but at double the fL it really felt like you were looking at an outdoor scene in a way I had never experienced. Just my bias.

I had hoped to be able to recreate this with a scope screen a little smaller than yours.

Art

hello guys
hi Tryg, hi Art !

well like you Art i'm in the process of upgrading my 1.4 400cm wide scope MP screen with something else. I want a curved 400cm scope model, with black velvelt frame.
If I had 5.5meters wide room i'd go with a non perf (yes !) as Alan reminded me: non perf all the way, purest video form. And i kinda agree: you can sit anywhere and have gain. And emulate very effectively the sound coming from the screen.
Now in my main room I can't or I'll have to switch to a 300cm wide screen but i want to keep the big image :D :D

So what options ?
I recently in February at the I.S.E. saw the new SR supreme curved scope screen in action, it was about 350cm wide i'd say (rough guess) with CP2 fabric and probably black scrim.
The projector was a big RUNCO 3DLP with lots of lumens i'd say given the size of the pj !!!! and the image was STUNNING ! (hd dvd of KING KONG): bright, contrasted, no structure. (which means the CP2 accomodates well lots of lumens while MP holes don't: there's a limit of FTL above wich the MP become visible and so viewing distance increases solution (lol): go big !!! so the viewing distance HAS to increase anyway).
But as said the pj threw away lots of lumens, i'd day maybe 2000+ ansi ??
The SR "real gain" is around 0.8.
The curvature really worked well even as I was standing on the right side, really not well placed. Not even seated on right of row 2. (sound was ADA + RBHS). And it was bright !
So that really convinced me of the benefit of the curving with the anamorphic lens.
I'd recommand without hesitation this configuration: LUMENS (calibrated 1200ansi or more (advised: more) + CURVED SR CP2. Stunning. (Art, truely stunning picture)

What about people with an RS1 or an HD1 then ? ie around 500-750 ansi lumens ??
If one wants a large screen of course :D
I'll experiment a MP 1.4 gain from another manufacturer and see how the visibility of the MP and paint goes compared to my current model (HHall, visible paint at 5meters on bright scenes). if conclusive, then this will be the compromise imho for RS HD1 owners who want scope AND big. (and curved, this is really cinematic and improves the reflected brigthness tothe audience also ! and reduces or suppress the pincusssion of the lens).

voilà :)

Mark,
When I watched quite a bit of King Kong at 23fL it was a totally different experience and the first time in a while I could say I felt like it was a step up. On my system and with thr RS1 on the same screen the outdoor scenes are very satisfying but at double the fL it really felt like you were looking at an outdoor scene in a way I had never experienced. Just my bias.

I had hoped to be able to recreate this with a scope screen a little smaller than yours.

Art

i agree totally: i'm in your camp, people who love the snap, punch of a giant plasma or tv (20FTl or more) rather than 6-12ftl.
the image is so more lively and engaging (side effect: bad compression revealed so sources have to be "clean")

http://i127.photobucket.com/albums/p146/CarlosMeat/Perfs.jpg




Pic of 1080 x 1920 three chip DLP pixel structure compared to perf size in Stewart fabric on an 11' wide 16x9 screen.

Art

Art,

I hate to steal one of CINERAMAX's pictures to illustrate my point (his photo shop chops are practically masterpieces so it's probably a felony...plus he probably has them trademarked). This pic is basically like your theater. Now if these people were sitting up they would probably get 2.5 gain or more. I think you would be very surprised at the performance of this screen. They are not very expensive so it's definitely worth experimenting with. But I'd be willing to bet you likely wouldn't be satisfied with another screen after you got used to it. Just a warning.

http://cineramax.com/images/Helene-Elevation.jpg

Pultzar has a RS1 on a 6' x 14" High Power. He says it's too bright!

I'm using a DIY 110" diag 1.24 gain WilsonArt Designer White laminate screen. I'm getting about 15 FtL in normal lamp mode and it seems plenty bright. There is a subtle texture that is present, but it isn't distracting; I like it a lot for the money. I'd love to get a 110" ST 130, but I'm getting 90% of the performance for 5% of the cost ($150). I'll probably get one eventually but this will do for now.

Art,

I hate to steal one of CINERAMAX's pictures to illustrate my point (his photo shop chops are practically masterpieces so it's probably a felony...plus he probably has them trademarked). This pic is basically like your theater. Now if these people were sitting up they would probably get 2.5 gain or more. I think you would be very surprised at the performance of this screen. They are not very expensive so it's definitely worth experimenting with. But I'd be willing to bet you likely wouldn't be satisfied with another screen after you got used to it. Just a warning.

http://cineramax.com/images/Helene-Elevation.jpg

Pultzar has a RS1 on a 6' x 14" High Power. He says it's too bright!\
Tryg,
I'm not doubting the quality of a High Power screen , properly employed, only that doing the math shows that if I placed the projector at 9' high only the center seats in the middle row and the same in the back row would be in positive gain, all the rest would be 0.7 to 0.8. What would work best for me it seems is a low to moderate gain angular reflective screen.

I was thinking Studeotech 130 or Ultramatte 150 as possible choices. Not to mention the nice scope screens with motorized side masking.

I can see that in the right install the High Power could be a tremendous choice.

Art

http://i127.photobucket.com/albums/p146/CarlosMeat/Perfs.jpg




Pic of 1080 x 1920 three chip DLP pixel structure compared to perf size in Stewart fabric on an 11' wide 16x9 screen.

Art

hi Art
this was from the HT5000 ?

what's you point? moiré, mperfs visibility vanished at which distance ?

y not a 1.5 gain screen from da lite do you think is to bright

Screen Gain – GrayWolf II high contrast gray screens have a screen gain of 1.8 for enhanced image viewing excellence
Gray Base Screen Surface-GrayWolf II™ gray-base formula are designed to enhance black level, shadow details and contrast for screens DLP™, LCD, D-ILA, and LCOS projectors.
Flexible Viewing- Extra large black borders for true 16:9 cinematic experience.
Viewing Angle- Wide viewing angle (>100 degree, total) allow for wider seating configuration.
The “smooth-secure” system renders a flatter installation in various temperature conditions
Features a “fast-lock” system for quick and secure setup for a virtually wrinkle-free screen
so what about the optoma sreen is that like the dalite hp so wide viewing angle 100 degree ? it is glass beaded to :confused:

I just finished building a 114" diag (105.6 x 44) 2.4:1 scope screen using the white rubbery side of blackout cloth for the screen material. I am guessing it is around 1.0 gain. It seems plenty bright to me and a huge step up from projecting onto a dark tan wall ;-)

\
Tryg,
I'm not doubting the quality of a High Power screen , properly employed, only that doing the math shows that if I placed the projector at 9' high only the center seats in the middle row and the same in the back row would be in positive gain, all the rest would be 0.7 to 0.8. What would work best for me it seems is a low to moderate gain angular reflective screen.

I was thinking Studeotech 130 or Ultramatte 150 as possible choices. Not to mention the nice scope screens with motorized side masking.

I can see that in the right install the High Power could be a tremendous choice.

Art

From the pictures I've seen of your theater, Art, I don't think the HP would be a good choice for you. This from someone who has become a serious HP evangelist. Tryg is right, though - once you see the HP image, you want it. It's that good. But I think your seating is too wide and your projector mounted too high even to consider it. Although I haven't seen the RS1, I think it's safe to say that your guests in the outer seats would be getting a vastly different experience than the ones in the middle. It's hard to imagine a better screen than the HP if a person's theater is narrow and the projector can be mounted low, or if the room is long and the seating is further back. I just recommended it to a friend who bought a Pearl, but his seating is similar to mine - narrow, with the pj mounted low.

HP 2.8 would require a clean picture (attention mosquitoi noise, bad compression).

again i can't stress enough how luminous the image was at the ISE on that curved SR (it's mainly the curving and the projector brigthness that did that) while sitting aside from the right part of the screen (!!!).

The High Power is a great solution.

1. Due to its retroreflectivity no other screen can deliver its uniformity on a flat plane. when going scope

2. It can deliver almost 3 times the light of a matte white screen.

3. You will not see the surface.

Tryg,

I'm intrigued by # 3... I am seeing the surface of my Studiotek 1.3 gain screen with the RS1 where I don't see the surface when using my CRT. The CRT is ceiling mounted and the RS1 is level with the center of the screen. What is causing me to see the surface - the higher lumens of the RS1 or the (lack of) projection angle?

I guess I assumed two things about the HP that I'm wondering if I've been wrong:

1) the higher gain would cause the screen surface to show more
2) higher light output means sacrificing black level

hi Art
this was from the HT5000 ?

what's you point? moiré, mperfs visibility vanished at which distance ?

Just that the perf size is much much smaller than the pixels. In this case it would take at least six perfs to be as larger as a pixel. The perfs are however visible more due to their contrast not their size.

For me in the front row I can't see the perfs but I have a few friends with 20:10 vision who say they can and clearly.

Art

From the pictures I've seen of your theater, Art, I don't think the HP would be a good choice for you.


Agreed.

Art

Just that the perf size is much much smaller than the pixels. In this case it would take at least six perfs to be as larger as a pixel. The perfs are however visible more due to their contrast not their size.

For me in the front row I can't see the perfs but I have a few friends with 20:10 vision who say they can and clearly.

Art

hey :)

there's a certain FTL level above which indeed perforations and /or paint become visible. it's tricky.....
i should have sit at the first row during that RUNCO demo to see if the big lumens revealed the CP2 fabric or not. :confused:

no matter which fabric i choose (stewart-like with a little gain or CP2) it will be curved scope.

Same setup as Tryg, and it is Awesome. Currently using my Sharp z12000 zoom method and it looks great. RS 1 on the way.

i should have sit at the first row during that RUNCO demo to see if the big lumens revealed the CP2 fabric or not. :confused:


You cannot see the CP2 weave once you are a few feet back - the holes are way too small.

I took a picture of CP2 holes a while ago, which you can see here - the image is the letter 'e' in single pixels from a 720p projector.

http://gallery.avsforum.com/data/508/medium/letter-e.jpg

Compare that to Art's image above where you can see a big perf in each pixel - screen size for this image was similar to Art's.

Mark

Art,

I'm not recommending the HP for your application, but I have measured a sample of of this material. This is how it measures:

Measurement conditions:

PJ mounted 2x screen width (actual width, not diagonal) from screen. PJ mounted .16x screen heights above top of screen material (16% PJ offset). Specifically the screen is 108"x60". The PJ lens is 18' from screen. The center of PJ lens is mounted 9" above top of screen material.

Measurements taken from the position of the viewers eyes when seated in the prime seat on a typical couch:

Color shift imparted by screen as measured in center: +.0023x / +.0043y
Gain measured at screen center: 1.17
Color shift imparted by screen as measured at right edge: =.0013x / +.0049y
Gain measured at right edge: 1.17

Conclusions: The HP imparts a small, but visible, color shift which can be calibrated out of the image, if desired, by an ISF using a spectroradiometer type sensor. The side to side brightness uniformity is virtually perfect. The side to side color uniformity from the prime seat is exceptional, deviating no more than .001 in x or y.

Measurements of the center of the screen taken from the eyes of a viewer seated 30 degrees off center:

Color shift imparted by the screen: +.0013x / +.0033y
Gain: .76

Measurements of the center of the screen taken from a eyes of a viewer seated 45 degrees off center:

Color shift imparted by the screen: +.0013x / +.0033y
Gain: .75

Conclusions: 36% reduction in gain measured from viewers seated to the sides. No significant color shift added compared to measurements from prime seat. The correction to counterbalance the color shift of the screen will work for all viewers regardless of viewing angle.

Caveats: I didn't take measurements at the top and bottom of the HP screen and can't say how uniform it is in the vertical dimension.

Comparisons:

The Carada BW is an exceptionally uniform and accurate screen material that measured at 1.11 gain, despite its 1.4 gain rating. Measured from 30 degrees its gain is reduced by 13%, and from 45 degrees its gain is reduced by 29%.

The Stewart ST130 is exceptionally color accurate, measures at 1.3 gain, and as a result of its higher gain has reduced color and brightness uniformity compared to the BW material, but is still quite good. Didn't measure its gain reduction from 30% angle, but it is likely somewhere around 30%; from 45 degrees its gain measured a reduction of 40%.

It is interesting to note that the ST130 and the HP are not all that much different when measured from the position of a side viewer. I wish that I had been able to measure the ST130 from 30% so that I would know for sure, but based on the other brightness uniformity measurements I took of it, I think that this is a conservative estimate.

Glenn

Cool Glenn.

BTW, a couple people seem to now be mentioning seeing the sparkly screen structure of the Studiotek, with their RS1s. Previously I did not think that was a problem with that screen, the "sparkly screen sheen" being reserved for the high-gain screens like the Silverstar.

I've read that the Carada BW material, while giving some gain, nonetheless really "disappears" and you don't notice screen structure with that screen. Can you comment? Thanks.

what about vutec silverstar high gain 6.0 wow is it good for the rs1 ? it is in AV web pg

I'm going to be using Sandman's SMX material - 124"W 2.35 setup. I might have missed it but I don't think I saw any other posts from SMX / RS1 users? I'm in the 3rd round of the pre-buy so I'll report back in about a month :(

Art,

I'm not recommending the HP for your application, but I have measured a sample of of this material. This is how it measures:

Glenn

Thanks from me Glenn, your measures validate my very rough angle/gain calcs pretty closely.

What was your perception of black levels with the HP ?

Tryg,

I guess I assumed two things about the HP that I'm wondering if I've been wrong:

1) the higher gain would cause the screen surface to show more
2) higher light output means sacrificing black level

Hi Ian,

read my High Power review in the screen forum

what about vutec silverstar high gain 6.0 wow is it good for the rs1 ? it is in AV web pg

We had a piece at my HT 5000 demo and on low lamp we measured 45fL ! :D

Art

Art,

I'm not recommending the HP for your application, but I have measured a sample of of this material. This is how it measures:

Measurement conditions:

PJ mounted 2x screen width (actual width, not diagonal) from screen. PJ mounted .16x screen heights above top of screen material (16% PJ offset). Specifically the screen is 108"x60". The PJ lens is 18' from screen. The center of PJ lens is mounted 9" above top of screen material.

Measurements taken from the position of the viewers eyes when seated in the prime seat on a typical couch:

Color shift imparted by screen as measured in center: +.0023x / +.0043y
Gain measured at screen center: 1.17
Color shift imparted by screen as measured at right edge: =.0013x / +.0049y
Gain measured at right edge: 1.17

Conclusions: The HP imparts a small, but visible, color shift which can be calibrated out of the image, if desired, by an ISF using a spectroradiometer type sensor. The side to side brightness uniformity is virtually perfect. The side to side color uniformity from the prime seat is exceptional, deviating no more than .001 in x or y.

Measurements of the center of the screen taken from the eyes of a viewer seated 30 degrees off center:

Color shift imparted by the screen: +.0013x / +.0033y
Gain: .76

Measurements of the center of the screen taken from a eyes of a viewer seated 45 degrees off center:

Color shift imparted by the screen: +.0013x / +.0033y
Gain: .75

Conclusions: 36% reduction in gain measured from viewers seated to the sides. No significant color shift added compared to measurements from prime seat. The correction to counterbalance the color shift of the screen will work for all viewers regardless of viewing angle.

Caveats: I didn't take measurements at the top and bottom of the HP screen and can't say how uniform it is in the vertical dimension.

Comparisons:

The Carada BW is an exceptionally uniform and accurate screen material that measured at 1.11 gain, despite its 1.4 gain rating. Measured from 30 degrees its gain is reduced by 13%, and from 45 degrees its gain is reduced by 29%.

The Stewart ST130 is exceptionally color accurate, measures at 1.3 gain, and as a result of its higher gain has reduced color and brightness uniformity compared to the BW material, but is still quite good. Didn't measure its gain reduction from 30% angle, but it is likely somewhere around 30%; from 45 degrees its gain measured a reduction of 40%.

It is interesting to note that the ST130 and the HP are not all that much different when measured from the position of a side viewer. I wish that I had been able to measure the ST130 from 30% so that I would know for sure, but based on the other brightness uniformity measurements I took of it, I think that this is a conservative estimate.

Glenn


Thanks Glenn , tons of great info there. :)

Art

Cool Glenn.

BTW, a couple people seem to now be mentioning seeing the sparkly screen structure of the Studiotek, with their RS1s. Previously I did not think that was a problem with that screen, the "sparkly screen sheen" being reserved for the high-gain screens like the Silverstar.


I often saw this structure with my StewartTek 1.3 - seating 12' from screen - Barco 812 CRT. The Screen Research CP2 I now use is completely "clean" in this respect. It's difficult to make an objective comparison, given that I am in a new room and using a new projector technology, but subjectively I much prefer the CP2 - it's completely transparent to the image - no holes - no sparklies - no sheen.

Mark

I'm sure there's a 3 dimensional scientific mathematical calculation, but that hurts my brain. :p

A simple unscientific way of calculating this would be use the center of the screen as reference. If your projector is ceiling mounted calculate the angle from the lens to screen center. Say this number is 15 degrees

Now calculate the angle of the viewers eyes in the off center seating location to the center of the screen. Say this number is 10 degrees.

Total 25 degrees = 0.8 gain

There is actually a fairly simple formula to calculate this angle. It is


angle = arccos( d / (d^2 +v^2+h^2)^(1/2) )

where d is the distance from the screen, v is the distance off axis in the vertical
and h is the distance off axis in the horizontal.

Your "add the angles" formula is not a bad guess if the angles are very small.
However, in the case you describe the actual angle is 20.76 degrees rather
than 25. Given the steep drop off in the gain of the HP in the 10-20 degree range
an error of even a few degrees could be quite significant.

If you already know the angles you are off center in the vertical and horizontal
plane the calculation above becomes


angle = arccos( 1 / (1^2 +tan(angle1) ^2+tan(angle2)^2)^(1/2) )

For what it is worth Art if you did your calculations using the sum of angles method
I would expect more of your back rows would be in a positive gain zone than
your calculations might have suggested.
However, there is no getting away from the fact that the vertical offset
would be the deal breaker for the HP in your setup.

There is actually a fairly simple formula to calculate this angle. It is


angle = arccos( d / (d^2 +v^2+h^2)^(1/2) )

where d is the distance from the screen, v is the distance off axis in the vertical
and h is the distance off axis in the horizontal.

Your "add the angles" formula is not a bad guess if the angles are very small.
However, in the case you describe the actual angle is 20.76 degrees rather
than 25. Given the steep drop off in the gain of the HP in the 10-20 degree range
an error of even a few degrees could be quite significant.

If you already know the angles you are off center in the vertical and horizontal
plane the calculation above becomes


angle = arccos( 1 / (1^2 +tan(angle1) ^2+tan(angle2)^2)^(1/2) )

For what it is worth Art if you did your calculations using the sum of angles method
I would expect more of your back rows would be in a positive gain zone than
your calculations might have suggested.
However, there is no getting away from the fact that the vertical offset
would be the deal breaker for the HP in your setup.


Having been away from trigonometry for thirty three years, I didn't assume that the angles were summed but that it would simply further reduce the gain to some degree.
There are only three seats in the back row and five in the other two (prime seating area) so it would make almost no difference. My goal is to use a low gain screen and a projector with sufficient lumens for this not to come up anyway. I didn't sum the angles just fudged upward a bit and the result was all seats in the front row had were in negative gain, all but one in the middle row and two in the back row.

Thanks for the info, I think it adds a lot to objectivity. A similar wake up call came up in the 2.35:1 forum regarding anamorphic lenses.

Art

No problem Art,

I was aware that your goals were different from "can I use a HP screen".
Just thought I would post this so that others considering this screen
could do a quick calculation of the offset. I have learned a lot from all of you guys
on this forum but my lack of knowledge of video limits how much I can contribute.
Being a working mathematician I don't get that many chances to give back with
something that I actually do know a little about . ;)